Along with the development of a 3rd Generation (3G) network, there are more and more 3G users, and respective operators throughout the world have started to lay out a 4th Generation (4G) network. However, the reality is that the vast majority of current terminal users are 2nd Generation (2G) users; therefore, most of user data is born in a 2G network, which leads to the condition that the 2G network is very busy, but most of resources of the 3G/4G network are idle in most of the time.
At present, multiple network systems can be integrated in one piece of terminal equipment, but different network systems correspond to different subscriber identity module cards substantially. Because different subscriber identity module cards are charged respectively, a subscriber identity module card cannot be switched to a network system corresponding to another subscriber identity module card when being used for initiating a service by a user. Therefore, the network traffic distribution of various services cannot be realized, and the network resources of respective networks cannot be maximally utilized.